The present invention relates to an apparatus for discriminating an audio signal, and more particularly an apparatus for automatically discriminating the audio signal as either an ordinary vocal sound, e.g., speech, or a musical sound.
A conventional method of discriminating an audio signal comprises the steps of converting the analog form of the audio signal into a digital form, and sensing to discriminate the characteristics of the digital audio signal. Namely, the analog audio signal is converted into a digital signal whose features are analyzed so as to discriminate the audio signal as an ordinary vocal or musical sound. However, this conventional method requires an artificial intelligence device of high cost together with a complicated procedure thereof.
The presently available small-sized video systems such as used for video data processing and cable television, provide audio systems which suffer an inherent limitation in the ability to reproduce audio signals. Such small-sized systems process the vocal and musical parts of the audio signal in the same manner, so that the vocal and musical parts may not be lively and dynamically reproduced. In order to overcome this drawback, if the audio signal represents the vocal sound, the frequency band of the dynamic range is reproduced without modification, while, if the audio signal represents the musical sound, the low and high frequency band parts of the dynamic range are boosted. Then the musical sound is dynamically and lively reproduced.
To this end, the reproduction of the received audio signal must be performed on the basis of a decision signal that is produced to discriminate the audio signal as either an ordinary vocal sound or a musical sound. However, a small-sized system needs a digital processing means of high cost to discriminate the audio signal as ordinary vocal or musical sound, and the digital processing means requires a complicated technology, so that the system occupies a large volume.